ACUTE MASS BURNS CAUSED BY O-CHLOROBENZYLIDENE MALONONITRILE (CS) TEAR GAS

The use of tear gas in controlling riots has been an accepted practice in many countries for the past four decades. In a recent event, a lar ge quantity of tear-gas canisters were used during a situation of unre st in a Hong Kong Refugees' Detention Centre. We report 96 cases of ac ute burn injury as an unpredicted side effect of o-chlorobenzylidene m alononitrile ICS) tear gas. There were 47 Females and 49 males with an age ranging between < 1 to 51 years. These burns were categorized as minor burns, with the total body surface area (TBSA) ranging from 1 to 8 per cent with mean percentage of 3. Most of the patients sustained superficial or partial-skin thickness injuries. Only two patients were admitted to the Prince of Wales Hospital Burns Centre because of deep er burns; debridement and skin grafting was required in one of them. T he mechanism of burn injury was due to the flame generated from the gr enade explosion, direct contact between the hot canister and the victi m's skin, and the effect of the chemical powder inside the canisters w hen it splashed onto the victim's body. We suggest that the noxious tr ansient effects of tear gas are underestimated, Furthermore varying cu taneous effects and deep burns may result from its uncontrolled use du ring riots. There is a continuing need to reassess the potential toxic effects of CS tear gas as a riot control agent and to debate whether its future we can be condoned under any circumstances.